As the cost and physical form factor of radio-frequency (RF) components and subsystems has fallen, and integration and available bandwidth has risen, many new applications of wireless technology have become practical and/or commercially viable. In many cases, this trend results in the viability of adding wireless functionality to existing products to either add features or overcome limitations of the device. In other cases, the availability of small, integrated, low cost RF devices and modules make viable accessories which improve or overcome some limitation of existing products.
One example of this is an article locator. The article locator is a small wireless device attached to an article which a forgetful owner may frequently misplace, such as a TV remote control, car keys, cell phone, MP3 players, audio equipment, Personal Digital Assistant (PDA), or any other type of battery operated device. Typically, a number of location devices are sold with a base station. Pressing a button on the base station causes the base station to transmit a signal to the wireless article locator. The article locator upon receiving the signal from the base station emits an audible, visual or vibratory alarm enabling the user to locate the article attached to the wireless device.
Adding new and possibly unrelated functionality to commonly used articles creates numerous obstacles. Accessories, such as the article locator, usually add to the physical form factor of the attached article. The physical form factor refers to the conventional physical outside appearance and shape of an article. Changing the physical form factor generally requires the user to accept a penalty in exchange for the utility of the wireless feature.
For example, a remote control device may be ergonomically designed to be evenly balanced and to be comfortably held in the hand of an operator. The operator can point the remote control device and press the buttons on the remote control device at the same time.
Attaching a wireless locator device to the top or bottom of the remote control device disrupts these ergonomic characteristics, including disrupting any balancing aspects of the remote, the way the remote may rest on a coffee table or on top of a television, and the way that the remote is normally operated. For example, it may not be possible for the operator to hold the remote and press the buttons at the same time with the same hand, since the wireless device may obstruct certain movements of the fingers on the top of a remote control key pad. Integrating wireless functionality inside a device at the factory burdens all manufactured devices with the cost of the additional functionality, which may only be used by a fraction of the purchasers.
It is often either cumbersome or impossible to add the desired functionality to an existing device, particularly if no external data interface is provided. For example, it would be advantageous to be able to convert a typical Infra-Red (IR) television (TV) remote control to use Radio Frequency (RF) signals in order to remove the need for line-of-sight between the remote control and the TV. Various accessories have been marketed implementing this function, but they have not been particularly successful because of the difficulty of attaching a universal external IR receiver to the multiplicity of different remote control form factors.
In addition, most batteries have certain disadvantages. It is not generally possible for a user to determine battery life. It is also not possible to turn a battery off other than by removing the battery from the device it is powering.